I just came across Blekko today, they are an innovative search engine that has not been released to the public yet. They talk about how they will use slash tags to allow you to search more specifically for the content you are looking for. For example a search for "Cats / humour" will only bring up funny pages about cats. You can view their intro video here. The video looks great, but honestly it's hard to imagine how they will survive competing against Google. What's your opinion?